Areva MiCOM P921, Technical Manual, Page: 264 / 376

P92x/EN CT/E11 Technical Guide
Courier Database
Page 74/118 MiCOM P921-P922-P923
Code Event text Description
Associated
COURIER cell
0105 TRIP : t dF / dT 4 Trip t df / dt 4 -
0106 TRIP : t dF / dT 5 Trip t df / dt 5 -
0107 TRIP : t dF / dT 6 Trip t df / dt 6 -
0108 LATCHED RELAYS Latched Relay command -
NOTE : When the cell reference is different from 0, this means that an
event is generated the event takes place and another event is
generated when the event disappears.
When the cell reference is equal to zero , only the event is generated.
Twelve bits are available in the character String to describe the content of a Courier
cell.
When the event appears, the corresponding bit of the associated format changes to
“1”.
When the event disappears, the corresponding bit of the associated format changes
to “0”.
2.3 Setting Changes
This uses a combination of three commands to perform a settings change:
Enter Setting Mode- checks that the cell is settable and returns to the limits.
Pre-load Setting- Place a new value in the cell, this value is echoed to ensure that no
setting changes has taken place, the confirmation of the new setting value does not
achieved by this action.
Execute Setting- Confirms the setting change, if the change is valid then a positive
response will be returned, if the setting change fails then an error response will be
returned.
Abort Setting- This command can be used to abandon the setting change.
This is the most secure method and is ideally suited to on-line editors as the setting
limits are taken from the relay before the setting change is made. However this
method can be slow if many settings are being changed as three commands are
required for each change.
2.4 Systems Integration Data
2.4.1 Address of the relay
The relays can have any address between 1 and 254 included. The address 255
corresponds to the global address to which all relays and all the other slave
peripheries respond. The Courier protocol specifies that no response can be resent
from the slave periphery to the global message. This permits to avoid that all
peripheries respond at the same time creating by this way a conflict on the bus.
Each relay possesses an address settled on 225 in order to guarantee that in case of
his connection to the operating network, his address cannot create any conflict with
the address of another periphery already in exploitation. In order to permit to a new
periphery to be entirely operational, his address has to be settled. The address can
be modified manually in capturing the password, than in following the method of the
setting change through the user interface on the front plate of the relay.